The tests AF have so far done have involved tests to determine the flow paths of leaking fuel around the engines, this took the form of high-speed taxi runs using coloured liquid to simulate fuel, these were carried out in January.
In May, AF carried out taxi and flight tests of the new tyres.
The BA tests on OAF will be to validate the fuel tank liners. Not to belittle the vital AF tests, but OAF's tests are the big one. Success is vital if the C of A is to be returned soon.
Air France are working on the fuel tank liner mods, they started several months after BA and will benefit from the experience gained on OAF. But it is not certain what timetable AF are working to, at this early stage of the mods it would not be sensible of them to commit themselves.
BA's OAE is having the mods done, and OAG will follow soon.